This invention relates to the equipment used by mountain climbers and more particularly crampons which, when placed under climbing boots, are used to move over snow-covered slopes, or walls covered with snow and ice.
More particularly, it relates to a safety device which can be applied to all crampons presently on the market, as well as a new type of crampon equipped with such device.
In general, the existing crampons are formed essentially of a metal frame, formed of two individual frames, one for the front of the boot and the other for the heel, connected together by at least one system for length adjustment which makes it possible to fit the crampon to the toe of the boot. Each of these individual frames is provided with attachment lugs which make it possible to fasten the crampons to the boots by means of belts or straps, and has, at its bottom, a variable number of spikes which implant themselves in the snow or ice upon the advance of the mountain climber.
These crampons which constitute the prior art have a very serious defect during travel over snow, both on ascent and especially on descent, or more particularly when the snow has been softened by the sun, as is very frequently the case. It is a fact that snow has a tendency to accumulate below the crampon in the space between the spikes, filling this space more or less rapidly, thus preventing the spikes from playing their role, which then promotes sliding and therefore the fall of the mountain climber. This phenomenon, which is greatly feared by mountain climbers, takes place without their knowledge since it takes place under the soles of their boots. It is responsible for most of the climbing accidents which take place on snow and is therefore directly one of the main causes for fatal mountain climbing accidents.
At present there is no way of alleviating this very serious drawback, since none of the attempts made by the manufacturers, such as, for instance, different shapes of the teeth, coating with a silicone paint, etc., have given fully satisfactory results.
The failure of the prior solutions proposed to solve this problem is furthermore entirely understandable if one studies the reasons which cause the snow to fill the space between the spikes below the crampon, namely:
on the one hand, there is a mechanical hooking of the snow on the relief designs in the sole of the climbing boot and on the various parts of the length adjustment system which form so many points for hooking, as well as the fact of the packing of the snow between the spikes which, due to their distribution, thus define a space which forms, so to speak, a mold;
in addition to this purely mechanical hooking there is a thermal bonding coming from the fact that the metal parts of the crampon under the foot of the mountain climber form a cold assembly to which the snow easily adheres;
and, finally, the snow is compressed forcefully in the space present between the spikes by the weight of the climber so that during each step it is subjected to vertical pressure and is packed even more if it has been softened by the sun and encounters a hard surface consisting of the sole of the boot and the frames of the crampon.